Process for making heavy basic carbonate of magnesium



la'tented Feb. 16, 1926.

UNITED STATES PATENT OFFICE.

BEBTRAND v1a. GnUNwaLn, or LLAMEDA, CALIFORNIA.

No Dr awlng.

To all whom it may concern:

Be it known that I, BERTRAND' B. GarmwALn, a citizen of Czechoslovakia, residing at Alameda, county of Alameda, and State 5 of. California, have invented new and use ful Improvements in Processes for Makin Heavy Basic Carbonate of Magnesium, which the following is a specification.

This invention relates to a process for manufacturing heavy basic carbonate of magnesium.

It is well-known that carbonate of magnesium has been-used for many years in the manufacture of means used for heatinsulating pur oses.

It is one ob ect of my invention to provide a rocess for manufacturin an improved lieavy basic carbonate 0 Y magnesium, as' hereinafter disclosed, which has various characteristics particularly adapting it for use for the purpose stated.

Another ob'ect of my nvention is a continuation of t e above process to form heatinsulating means, wherein the product of the above process is used as an ingredient.

My improved product has practically the sa'me'chemical composition as the li ht basic carbonate of magnesium but has istinctly different physical properties. It is considerably heavier and. has greater cementing or binding qualities. Also, contrary to the light carbonate of magnesium known here tofore, it does not, shrink in the drying.

Due to the latter qualities this roduct is. of great value as a binder in t e manufacture of heat insulating materials made from diatomaceous earth, light carbonate of magnesium, etc. It also serves as anexcellent-filler in the molding of articles from paper pulp. This product is also usedas raw material in the manufacture of an imesia, as'

proved light basic carbonate of ma disclosed in my co ending application Serial Number 723,152, ed I une 30, 1924.

.Following is a description of my'proces s I mixone partaof ground calcined magnesite with ten to fifteen parts of .water, and

introduce carbon dioxide gas into this mixture.- Due to the exothermic chemical reaction between the-carbon dioxide (C0,)

desired finished article.

previously to drying the same.

sistsxin introducing carbon? dioxide gas into Application filed June so, 1924. Serial No. 723,151.

and the magnesium oxide (MgO), the temperature of the mixture will rise gradually.

The heat formed by the chemical reaction, of course, varies with the proportions of water used. The proportions of water used should, therefore, be such that at the termination of carbonization the tem erature will be approximately 100 Fahren eit. When a. .tem erature of approximately 100 Fahrenheit is reached I stop the introduction of the carbon dioxide gas. I then allow the mixture to rest for a period of twenty minutes to several hours. During this resting period the carbonate of magnesium keeps on" ex anding in volume. When the proper p ysical consistency'is reached, it can be used immediately for any of the purposes mentioned above. In case it is desired to store this materal for any length of time, the mixture of carbonate of magnesium and water is cooled by adding more cold water. The product resulting from the above described process is a heavy basic carbonate heat-insulating means. Inguse, this product is mixed with asbestos or other suitablematerial and molded into theshape of the I then heat the molded productto a minimum temperature of 150 Fahrenheit to 250 Fahrenheit, The final resulting product is of the desired weight, of great strength and of the original molded shape, since the same does nots'hrink in drying.

I claim: 1. The process of manufacture of heavy basic carbonate of magnesium, which cona mixture of calcined magnesite and watery and iitilizing the resulting heat of reaction in the formation of the desired physical properties of the resulting-product.

2. The process of the manufatuie of heavy carbonate of magnesium, W ich con sists inintroducing carbon dioxide as into a mixture of calcined magnesite an water, utilizing the resultin heat of reaction in' the formation ofthe esired physical properties of the resulting product, and thereof time until the same has exfpandedv the proportion of the water being such that the temperature, due to the chemical reaction, shall reach. approximately 100 vFahrenheit at the termination of carbonization, then allowing the mixture to rest for further expansion, and terminating the expansion by the cooling of the mixture.

BERTRAND B. GRUNWALD. 

